In 'The Fat Trap,' Our Bodies Work Against UsTwo-thirds of Americans are overweight. And when many of them try to take off the extra pounds, their bodies fight to stay fat. Tara Parker-Pope, who described "The Fat Trap" in The New York Times Magazine, and Dr. Arthur Frank talk about why some people appear more biologically prone to obesity.

Two-thirds of Americans are overweight. And when many of them try to take off the extra pounds, their bodies fight to stay fat. Tara Parker-Pope, who described "The Fat Trap" in The New York Times Magazine, and Dr. Arthur Frank talk about why some people appear more biologically prone to obesity.

This is TALK OF THE NATION. I'm Neal Conan. You don't have to be a "Biggest Loser" contestant to know that there's a simple formula to lose weight: Eat less; exercise more. But as hard as that is, keeping weight off can wear down even the most determined.

New studies show that once we've gained weight, our bodies resist efforts to drop the extra pounds. And if we do manage to get them off, our bodies react as if they need to put that fat back on. It's not so much a matter of willpower, but evolution and chemistry.

The studies provide explanations - unfortunately, little in the way of solutions. If you've lost a significant amount of weight, call and tell us about your efforts to keep it off, 800-989-8255. Email us: talk@npr.org. You can also join the conversation on our website. That's at npr.org. Click on TALK OF THE NATION.

Later in the program, Facebook's compassion czar will join us. But first, the battle against fat and biology. Tara Parker-Pope's - Tara Parker-Pope; she's got the most difficult name to pronounce - it's only two syllables - I've ever seen - Tara Parker-Pope edits and writes for Well, the healthy living blog of the New York Times, and wrote the cover story of this week's New York Times magazine, "The Fat Trap." She joins us from a studio in New Jersey. Nice to have you back on the program.

TARA PARKER-POPE: Happy to be here.

CONAN: And this story is your story.

PARKER-POPE: You know, it didn't start out as my story. I mean, it started out as a science story on the science of weight loss, and I had a conversa - I was doing a variety of interviews and really was interested in the topic. But the more I talked to the experts, the more the story resonated with me, just so personally.

And it started to make sense of a lot of my own experiences, as someone who has struggled with weight problems - not my whole life but really, my adult life. And you know, I submitted the original story as just a story looking at the science. But in all my conversations with my editors, you know, I obviously took it to the personal level, to try to explain things.

CONAN: Mm-hmm.

PARKER-POPE: And one of my editors called me and said, you know, this really is your story. I really - I want you to share because I think that it adds a level of credibility to the story if you say that you've also struggled.

So it felt right. And then I decided to, you know, sort of come out as a health writer with a weight problem - which was very hard to do, but the reaction's been pretty positive.

CONAN: Pretty positive because there are so many in your situation.

PARKER-POPE: Well, it's true, but people can be pretty tough and judgmental. But I think that it was reassuring that even somebody with the knowledge and, you know, really I do have a lot of opportunity in my job, you know, to, you know, talk to some of the smartest people in the world about this issue, and I still struggle.

And I think that that was helpful to people to hear - that it wasn't just them; that once you do become overweight, it is very, very difficult to lose weight and to maintain the reduced weight. And, you know, the message is difficult. The message - you know, I pitched this story, why fat people stay fat. And I'm in that group.

So it's a hard message but at the same time, there's a lot of hope there because once you really know the science, and you really understand what you're up against, then you find the opportunity to - perhaps - possibly succeed or, you know, even better, accept yourself and not beat yourself up so much.

CONAN: The fundamental unfairness of it all seems to be that if you're - and I'm just making stuff up here - 300 pounds and you lose a hundred pounds, you get back to 200 pounds; a great achievement. To keep yourself at 200 pounds, you have to eat less, and exercise more, than the person who was 200 pounds to begin with.

PARKER-POPE: It's true, and there's a huge disadvantage - I mean, even at the lower weights. It doesn't have to be, you know, a person who's 300 pounds. Say, a - you know, a man or woman who hits 200 pounds and drops down to 150 and feels pretty - they've only lost 50 pounds, but they have the same problem.

The person who's naturally at 150 pounds can eat about 300 to 400 calories more than - or, you know, eat and exercise - exercise less, eat more, to the tune of 300 to 400 calories, compared to the weigh-reduced body. There's a biological backlash when you lose weight.

And your body changes. Your brain changes. Your gastric hormones change. All kinds of chemicals and hormones change. Your muscles change. Everything becomes more efficient and suddenly, you know, the same person who might go burn 200 calories on a brisk walk, you're only going to burn maybe 140 calories on that same walk. You're really at a disadvantage.

CONAN: And as you investigated this fundamental unfairness, you did find people who were able to maintain that weight loss, but it seemed as if they did so by enormous dedication.

PARKER-POPE: It really does require enormous dedication and unfortunately, it gets back to this issue of willpower. And, you know, I guess you can say it's just about willpower but really, how much is reasonable to ask of a person? You know, the people that I interviewed who had managed to successfully maintain weight loss, most of them lost a significant amount of weight and then put on about - you know - 20, 30 pounds.

And then those who succeeded sort of found a place where they could maintain a reasonable weight, but they still had to work very, very hard. And it was - you know, it's waking up every morning and weighing yourself, writing down every bit of food you put in your mouth, and really tracking it and reviewing it, and staying accountable.

It's exercising to the tune of 90 minutes to two hours a day. It's a tremendous - you know, the average person who has lost weight successfully and maintained it for at least three years, they exercise - it averages out to a four-mile walk every day.

You know, most people who have - who don't have weight problems, don't have to add an extra four miles of exercise every day to maintain their weight. But that's what these super-weight losers do. They really - every bite, every bit of exercise. And they really - you know, if you start doing the math, they really do deprive themselves about 300 to 400 calories a day to just stay at the new weight.

CONAN: That 300, 400 calories, that's a - that's a big muffin.

PARKER-POPE: You know, it's a big muffin, or it's a reasonable, you know, breakfast of an egg white and, you know, juice. And I mean, it can be - for a lot of people who have been dieting, you know, 300 or 400 calories is a meal. If you're not - you know, if you're on like, a 1,200-calorie-a-day diet, you know, it's like 400 calories a meal. So yeah, it's a giant muffin, but it's also a bowl of cereal and some juice and, you know, some reasonable, you know, fruit added to the mix. So it's a lot.

I have to say, I think a 300-, 400-calorie difference is a lot. And it's a huge amount of exercise. I think, you know, a brisk half-hour walk is, you know, 150 calories - maybe. So it's a lot of walking. It's a couple hours of walking.

CONAN: We're talking with Tara Parker-Pope; she's the author of "The Fat Trap," the cover story in this week's issue of the New York Times Magazine. If you've lost a lot of weight, call and tell us about your efforts to keep it off, 800-989-8255. Email us, talk@npr.org. We'll start with Chris(ph), and Chris is on the line - with us from San Antonio.

CHRIS: How are you doing today?

CONAN: Good, thanks.

CHRIS: I've actually lost weight twice. When I was young - very young - I was skinny, and I've got nothing but large people in my family, politely speaking. But we have all struggled with weight. And I lost it when I was - I started gaining weight at about 21, when I stopped riding bicycles and skateboarding, and doing everything I did when I was younger, and started drinking - 'cause alcohol doesn't help.

But I started gaining weight, and then I didn't gain much. And I got pudgy, and I got it off. And the second time, it was - I was close to 300 pounds, when it was - an old friend from high school was just like, look at the size of your arms. And I was like, are they that big?

Anyway, so I lost all the weight using a diet of no flour, no sugar whatsoever. And then I moved on to eating regular once I got down to a good weight. I still maintained a healthy diet, but it wasn't enough because I just gained the weight right on back. And here I am at 285 pounds again, and I'm doing it again.

CONAN: Hmm. So you're going to go back on that diet.

CHRIS: I'm doing the diet again, and it's actually starting to work already.

CONAN: Well, good luck to you, Chris. But I wonder, when you got down to that low weight again, you talked about starting eating the same way you used to. Was it because you were hungry all the time?

CHRIS: You know, it's not so much that, but if you think of what flour and sugar entails, it is a lot. I mean, that's pastas, lasagnas, breads, any kind of cakes, pancakes, waffles. I mean, sugar - I ate fruits and vegetables and potatoes, and things that naturally contained sugar, but I didn't add any sugar to anything.

And so it was more like, you know, what your panelist was saying. You're depriving yourself of things that - you know, your friend who's skinny will have a burger, then ask for extra Texas toast to go with his burger, and drink a Dr. Pepper and have three of them. And he weighs 175 pounds. And I ride 20 miles a day on my bicycle, and I can't seem to keep it off.

CONAN: And Tara Parker-Pope, that's a typical story.

PARKER-POPE: It's so typical, and it's really amazing how consistent the stories are. And what the research is showing is that once you do lose weight - you know, they're looking at these various hormones that affect hunger and weight regulation, and what they find is that even a year after you've stopped dieting, if you haven't put that weight back on, these hunger hormones are still at levels that are sending powerful signals to the brain that make you feel more hungry, you know.

And MRI scans show that brain even responds differently to foods. You know, you look at a food and your - the parts of your brain that affect your ability to - you know, willpower, restraint, there's less activation; there's more activation in desire and reward.

So we go through these changes. Your muscles are less efficient, so you're not burning as many calories when you do everyday activity and moderate exercise. So it's very, very difficult. And that story is absolutely typical.

And, you know, somebody that succeeds at weight loss doesn't really stop, doesn't really sort of go back to normal - ever. They find a new normal, which is very different than normal for most people.

CONAN: Chris, good luck.

CHRIS: Thank you very much, I appreciate you taking my call.

CONAN: OK, this is an email we have from Amy(ph) in San Jose: Many of us in the blogosphere have been gravely concerned with Tara Parker-Pope's story in the Sunday New York Times. We all follow Dr. Esselstyn's vegan, no-added-oil, plant-based food plan for our health. Bill Clinton brought the news out to the masses last year.

We've all lost of a lot of weight, and our health has never been better. We hope she considers looking into his profound research. It works. You are never hungry.

And I wonder if you've gotten responses like that since your article came out.

PARKER-POPE: Well, everybody who has found something that works for them believes that that's the solution. And for those people, it is the solution. But again, I would say that these people didn't adopt a vegan diet, lose weight, and then go back to the way everybody else eats. A vegan diet can be very restrictive.

And, you know, this works for that group of people, and that's great. And for many people, that will work. For other people, maybe a permanent kind of Atkins diet would work. For many people, Weight Watchers works. But we have to look - step back, look at the big numbers. Depending on what study you look at, you know, diets have an extraordinarily high failure rate. Anywhere from 5 percent to 20 percent of people actually achieve long-term weight loss. So that means, you know, 80 to 95 percent of people fail. So there are people who succeed, and those people give us hope because there is a way.

But you have to find the way that works for you.There are some people who would find it very difficult to adopt a vegan diet. You know, the person who is, you know, a caregiver for a parent with Alzheimer's, you know, they don't have the luxury of exercising two hours a day. You know, they don't necessarily - they can't necessarily go to the market and buy organic food.

I mean, everybody has things they're dealing with, and I think that what works for one person doesn't necessarily work for everybody.

CONAN: We're talking with Tara Parker-Pope, of the New York Times, about her magazine cover story this week, "The Fat Trap." If you've lost a significant amount of weight, call and tell us about your difficulties - or not - keeping it off, 800-989-8255. Email us, talk@npr.org. Stay with us. I'm Neal Conan. It's the TALK OF THE NATION, from NPR News.

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CONAN: This is TALK OF THE NATION, from NPR News. I'm Neal Conan. More than two-thirds of Americans are overweight, and this time of the year, many of us resolve to lose those extra pounds. As we've heard, effort may not be enough. Losing weight is difficult; keeping it off pits our willpower against evolutionary biology.

Our brains can perceive dieting as starvation; do everything it can do to put those pounds back on. NPR's Patti Neighmond reported on this recently. You can find her piece at npr.org. If you've lost a significant amount of weight, call and tell us about keeping it off; 800-989-8255. Email talk@npr.org. You can also join the conversation on our website. Go to npr.org. Click on TALK OF THE NATION.

Our guest is Tara Parker-Pope, who wrote the piece in the New York Times magazine, "The Fat Trap." She mentioned earlier she gets the option of talking with some of the smartest people in the business. So do we. Over the years, we've enjoyed talking with Dr. Arthur Frank about these issues from time to time. He's the founder and former director of the George Washington University Weight Management Program. He's been kind enough to join us here in Studio 3A. Doctor, nice to have you back on TALK OF THE NATION.

ARTHUR FRANK: Thank you, sir, it's a pleasure.

CONAN: And I wanted to ask you: This is - we're talking about some of these studies; they have confirmed what's been your experience for a long time.

FRANK: Oh yes, indeed. This is a difficult disease to manage, and I think partly because so much of our culture is organized around the task of losing weight, and so little of it is organized around the task of maintaining that weight loss. There are weight-loss doctors, and there are weight-loss programs, and weight-loss diets and books and pills. But there's very little attention addressed to the issue of maintaining that weight loss, which is an extraordinarily difficult problem.

CONAN: And have you been surprised by the research that shows these various hormones and other chemicals that prompt us to put the weight back on?

FRANK: No, not at all. In fact, this is what we have been anticipating for all these years; anticipating the realization that eating is a very highly regulated phenomenon, and we work on the assumption that all you have to do is to eat less. And it turns out that eating is not merely a matter of choice.

Much of eating is driven, intensely driven, by very powerful signals from the brain and from other organs, sending you signals to eat and to controlling your eating, controlling your hunger, controlling your sense of satiety, controlling your regulation of your eating behavior - very highly, very intensely structured hormones and regulating systems that control your eating behavior.

CONAN: And these...

FRANK: And these are set wrong in people who are overweight. They're set at an abnormal level. That's the nature of this disease. And simply losing weight does not reset the signaling systems. So when you say, all you have to do is to eat less and exercise more, it's sort of like saying to a person who is depressed, all you have to do is pull yourself together.

It doesn't work that way. If I could pull myself together, I wouldn't be depressed. Or saying to a person with asthma, all you have to do is just breathe easy. If I could breathe easy, I wouldn't have asthma. If I could eat less, I wouldn't have the problem of obesity.

And so what we've got is an extraordinarily powerful system that's driving your eating behavior - and driving it with intensity to actually recover your weight, the weight at which you were starting when you started to lose weight.

CONAN: I wanted to bring you both in on this question - this is an email from Tom(ph) in Portland, Oregon: The dynamic you describe in your article is certainly plausible but seems incomplete. Fundamental biological factors, such as genetics, can't have changed that much in the last 20 years and during that time, Americans are supposedly fatter than they were, and fatter than other people around the world. What else has changed? Could it be endocrine disrupters, as some claim?

Tara Parker-Pope?

PARKER-POPE: You know, this is a really common question in response to the article, and I think the way to answer it is that, you know, our genetics - you know, we've always - our bodies have always liked to hold on to fat, which is a - it's an adaptive - you know, adaptive response in a famine or, you know, in a time when food is not plentiful.

It's only been in very recent history that food has become so abundant. Even our grandparents, you know, who lived through the Depression, didn't just have, you know, free access to food the way we do. So it's not that our genetics have changed. It's that the environment has changed, and the expression of these genes has been triggered for many people.

So, I mean, there may be other factors, and the doctor can address those. But I think that this is a point of confusion. No, our genes are the same. You know, the genes, our genetics have always favored gaining weight and holding on to weight. It's only in the current environment that the sort of negative expression of those genes has been manifest.

CONAN: Dr. Frank?

FRANK: This is happening all over the world, even in parts of the world which are relatively remote. But what is happening, really, is the availability of food. We now have a plentiful supply of food, essentially available to everybody - certainly in the United States, available to everybody.

And we have an extraordinarily simplified life existence. We have automobiles. We have computers. We don't work as hard, physically work as hard, as our forebears. So we have - on the one hand we have the opportunity to eat more, and we have the opportunity to exercise less.

And we are predetermined to do those kinds of things - to eat more. All of our genetics is driving us to do just that, to eat more and to exercise less.

CONAN: Let's get another caller in. This is James(ph), James with us from Toledo.

JAMES: Hello. I've lost weight, to the tune of 75 pounds, and gained it all back and more. And I've done that yo-yo probably - I don't know, two or three times in my adult life. I'm 41. And I guess the next question for me is: Would - does it - because I've been told that fat cells don't die, so they get smaller. So the question I have for the doctor, or the panel, would be that – would a, like a liposuction therapy when someone's down to a fairly close, reasonable weight to remove a lot of fat cells?

Or, I've heard there's an experimental freezing therapy that removes fat cells or kills fat cells; it's not invasive. I was wondering if those would be things that would actually help limit the amount of the - try to help regulate this intense desire to regain all that weight.

CONAN: Tara Parker-Pope, some of the people you write about - a very small percentage but yes, some people go for liposuction or other surgical techniques.

PARKER-POPE: Well, there's a difference between liposuction and weight-reduction surgery. With liposuction, there's been some very recent science showing that the weight does come back. I mean, what your body responds to is the loss of fat and a hormone called leptin that changes; it sends brain signals.

So removing fat by liposuction does not work, and there is a fair amount of research now supporting that. And in fact, it will just - the fat will just kind of bulge out somewhere else. And some people have been very unhappy with what happens after liposuction because they end up getting fat in places that it's much less desirable to have than where they had it removed.

Bariatric surgery is a different story. There is more success with bariatric surgery. But I have to say, it's also got a - only a certain number of people are candidates for that surgery. It's a high-risk surgery. I don't think it speaks to most people who have a weight problem. The doctor can comment on that as well.

But, you know, there is a failure rate with bariatric surgery as well. Some people out-eat the surgery. And they still have the hunger, and they have the, you know, cravings. So it's not really the solution for the country's weight problem.

CONAN: Dr. Frank?

FRANK: The regulation of eating behavior is such a complex phenomenon, it's probably one of the most complex biological regulating systems that exists. And simply removing fat cells is not going to solve the problem because there's a whole series - there are a whole series of events that occur to compensate for your loss of weight, and your loss of the fat cells, so that when you decrease the fat cells, there are a number of things that occur which override your decreasing the fat cells.

So you're probably not going to accomplish much. On the other - latter point of the bariatric surgery, the bariatric surgery is effective but it, too, is effective in the short term because eventually, people with bariatric surgery very frequently regain their weight because they've not solved the problem of the changing of the regulatory hormones.

And ultimately, we're going to have to do that if we want to manage this disease. I think in some ways, it sounds very discouraging. On the other hand, I'm very hopeful because what we've done is, we've identified many of the regulating hormones and regulating substances. We know what they are. We have a pretty good idea of how they work, and we're getting more sophisticated about how we can eventually control these things - which is what is going to have to happen.

CONAN: James, I'm sorry for not having better news for you.

JAMES: Well, it's, you know, one of those things where you - at least like the author - or, the writer of the article said, at least you know what you're up against. I mean, that's the reality of it for the vast majority of us who are struggling. It's just a lifelong struggle.

FRANK: Don't be discouraged because you can actually - it sounds so dismal, and it sounds so fatalistic and such a sense of futility - but you actually can override these regulators. I think what we're characterizing is the difficulty and the complexity of doing that, but it doesn't mean it cannot be done. We all know people who have lost weight and have successfully maintained it.

What is - the similarity among all these people is that they work very hard at the task of doing that. But I would not view this as futility; I would not view this as impossible. I would just say it's difficult but it is, in fact, doable if you want to devote that much determination to it.

CONAN: Tara Parker-Pope, as we mentioned at the top, this is, in part, your story too. Did you come away from this - writing this article and doing the research and talking to everybody - more discouraged, or less?

PARKER-POPE: No. It's interesting - I actually feel very optimistic about my future, and I was reassured when so many readers said the same thing to me. A reader, just yesterday, sent me an email that said she found the article sobering, challenging and comforting, all at the same time. And that's really how I felt when I learned this, and that's why I felt so strongly about sharing it in the way that I did. Because I do think it's hard. I don't think we do anybody a favor by saying, this is easy. It can, you know - of course you can do this because, you know, these commercials say oh, just believe.

It's so much more complicated than that. And if you're not in a situation where you really can fully devote yourself, then maybe the short-term strategy for you is to just take care of yourself. Take care of the body you have - eat well, exercise, try to develop these good habits.

And when you really can fully commit to what it takes and you're ready, then go for it. But don't look at it as just as six-week or 10-week or 20-week journey. I mean, this is a lifetime of change. And I tell myself, if I had kidney disease, I would commit myself to this for life. If I had epilepsy, I would say, this is the - these are the cards I've been dealt. And I think finally understanding that this isn't just about character; this isn't a failure on my part; this isn't that I'm weak-willed - I mean, I'm a very hard worker. And now that I sort of know what I'm up against, I'm like, OK, you know what? I think - I see, you know, I understand the challenge ahead of me, and I feel more equipped to take it on.

I also have been a lot, you know, kinder to myself. And I have stopped beating myself up so much - which I think is a huge step for everybody with a weight problem. I think it's the first step. You've got to kind of forgive yourself a little bit, and then start from there.

CONAN: Interesting email from Tristan(ph) in Salt Lake City: After losing 150 pounds over the past five years - yay! - I am still the fat girl, but I'm now - I'm the fat girl in a healthy body. Can you talk about ways to catch up emotionally, psychologically, with weight loss? It is self-esteem issues - the thinking that losing weight will be the end-all of problems. Even though I have accomplished the seemingly impossible, and I exercise nearly every day and I'm stronger and healthier than ever, my self-esteem is lagging. I find myself slipping into my obese ways of thinking; i.e., not looking at my reflection as I pass a window or a mirror, thinking I'm not good enough for relationships, etc.

So it's not just your body that sends those signals, Dr. Frank. It's your consciousness.

FRANK: It's part, also - our culture. Our culture is a culture which even though a large fraction of our people are overweight or obese, we still have a very negative view - with terrible social stigma, and terrible prejudice about the phenomenon of obesity - because people in general see this as a simple task. All you have to do is lose weight. All you have to do is eat less. And so there's a disapproval of people who are obese, and there's a prejudice about it. And what you've got is the consequences of years, decades, of having suffered that. And now, what you've got to do is to re-establish your role in the world. You're not a different person; you're just a different size and different shape. And there's a lot of work in reorganizing your social patterns, your emotional patterns, your intellectual patterns about how you want to maintain that weight loss.

CONAN: Dr. Arthur Frank, founder and former director of the George Washington University Weight Management Program. Also with us, Tara Parker-Pope, who wrote the article "The Fat Trap," that's on the cover of this week's issue of the New York Times Magazine. You're listening to TALK OF THE NATION, from NPR News. And Denise(ph) is on the line, Denise with us from Denver.

DENISE: Hi there. How are you?

CONAN: Good, thanks.

DENISE: Good. I am - I lost about 60 pounds. I had topped up at like, 200. And I know it doesn't seem super significant, but I'm - you know, I'm pretty short. I'm like, 5 foot. But I guess my point was - is, I wanted to stress that it is about numbers; you know, calories in, calories out, incorporating exercise. But more than anything, I always made my goal to be like. maybe half a pound a week - or even just maintain. And rather than stress myself out with that insistence that everybody can lose two pounds a week if they really focused - because when I do that, I don't succeed and I freak out, and I think I'm starving to death. So I've had a lot of success just keeping it small and relaxed.

CONAN: Good. I'm glad it worked out for you, and you've been able to maintain it.

DENISE: Yeah, I did for about a year, and then I stopped exercising as diligently. And it just - before you know it, like, I had gained 15 pounds. So, you know, I'm back on track. But for me, it is true. I have to exercise even if I'm counting calories. If I'm not exercising, the weight gets right back on.

CONAN: And again, Tara Parker-Pope, that's the story that so many people told you.

PARKER-POPE: It is really consistent. It's always interesting to listen to people's stories. And I think that's what happens - that, you know, sometimes life gets in the way. And you get busy; you know, you have a sick family member, work gets busy and then suddenly, the pounds are back. And this is actually what happened to me, that was so frustrating to me because I would - I really was being honest with myself. I knew what I was putting in my mouth. I mean, I trained for a marathon and ran a marathon, for goodness sakes. I mean, I was out on 20-mile runs. And I could not have exercised more. And, you know, it wasn't helping, necessarily. I wasn't losing weight. And it was very frustrating to me because I sort of bought into this notion, well, if you just, you know, eat right and exercise, you'll lose weight.

And it's really got to be much more precise than that. But at the same time, I don't think that - you know, exercise is there because it, you know, it makes us feel great and it give us pleasure, and it does help people maintain weight loss. But it's also true that people can exercise a lot and not actually lose weight. It's got to be a combination of changing eating - you know, really, a lot of vigilance about food and how much exercise. And this - it takes a lot of self-awareness to really tackle this problem.

CONAN: Denise, as you look ahead, do you see this as a lifetime commitment?

DENISE: Absolutely. I know that I feel happier at the smaller weight. And I actually do feel my mental health is so much better with exercising. So even if the weight does or doesn't stay on or off, the exercising is so good for my emotional well-being. So that is why exercise needs to be a priority for me.

CONAN: Well, Denise, good luck. Keep it up.

DENISE: Thank you.

CONAN: Appreciate the phone call. Dr. Frank?

FRANK: We talk about a lifetime dedication to this task. And in many ways, it is a lifetime dedication. But I have to emphasize - and I think from my perspective, and partly because I've been involved in some of the research about the medications and the hormones that are controlling eating behavior - I think we can look forward to better days in the future. It's not going to be this kind of futility, or this kind of difficulty, always.

I think we have an opportunity, perhaps in the next decade or 20 years, where we're going to be able to understand it well enough so that we can actually control it more - with much more sophistication and much more so it is less - this eternal struggle.

CONAN: Dr. Frank, as always, thank you very much for your time. Tara Parker-Pope, we thank you for your time, too. It's the TALK OF THE NATION from NPR News.

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